Hospital-Acquired Conditions (HAC) & The PSI-90 Score

What Are "Never Events"?

When you go to a hospital to heal, the last thing you expect is to acquire a new, severe injury or infection that could have been avoided. In the medical community, highly preventable errors are often referred to as "Never Events." The Centers for Medicare & Medicaid Services (CMS) officially classifies these as Hospital-Acquired Conditions (HACs).

Understanding the PSI-90 Score

To measure a hospital's ability to keep patients safe from these events, CMS uses a complex metric known as the Patient Safety and Adverse Events Composite (PSI-90). The PSI-90 is a single, risk-adjusted score that rolls up 10 different Patient Safety Indicators into one number.

Some of the critical indicators tracked inside the PSI-90 include:

• Severe Pressure Ulcers: Stage III and IV bedsores that develop because immobilized patients are not turned regularly.
• Falls and Trauma: Patients falling out of bed or while walking, leading to hip fractures or head injuries.
• Retained Foreign Objects: Sponges or medical instruments accidentally left inside a patient's body after surgery.
• Iatrogenic Pneumothorax: Accidentally puncturing a patient's lung during a medical procedure (like inserting a central line).
• Blood Incompatibility: Administering the wrong blood type during a transfusion.

How to Read the Data

When looking at PSI-90 or individual HAC scores, lower is always better. A score greater than 1.0 indicates that the hospital had more adverse events than what CMS predicted for their specific patient population.